Retinal glia (Muller cells) will be separated from rabbit retinae by a two step procedure of dissociation followed by unit gravity sedementation. These preparations are more than 90% homogeneous. Retinal glia will be used to study the kinetics of ion accumulation in potassium induced glial cell swelling. The rate and magnitude of the movement of 22Na ion, 86Rb ion (as the potassium surrogate), 45Ca ions and 36Cl ion will be measured in response to alteration of the ionic environment. The uptake of 3H-deoxy-d-glucose will be measured also as an indicator of metabolic activity. All of these measurements will be made using the technique of flow dialysis which permits successive measures of nuclide uptake over intervals as short as 6 seconds or as long as necessary. These studies will be performed for two cases, the accumulation of ions in response to potassium elevation and the restoration of ionic balances as glia recover from swelling when potassium concentrations return to normal. To determine the kinetics of this phenomenon, we will examine the ionic dependencies of ion uptake by altering the extra-cellular concentrations of Na ion, Ca ions, Cl ion and HCO3 ions. Once the kinetics and ionic dependencies are known we will study mechanisms underlying the ionic alterations by application of transport and enzyme blocking agents such as cardiac glycosides, stilbene derivatives and sulfonamides. These studies will provide the first step-by-step understanding of the ionic dynamics underlying the development and resolution of glial cellular edema.